Improvement in exhaust-valves for steam-engines



G. H. CORLISS.v Exhaust-Valve for Steam-Engines.

` No. 215.806. Patented May '27, 1879.

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NA PETERS. PHDTO-LITHOGRAFHER, WASHINGTON. D Cy UNITEDSTATES PATENTOFFICE.

GEORGEV H. OORLISS, OF PROVIDENCE, RHODE ISLAND.

IMPROVEMENT IN EXHAUST-VALVESl FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 215,806, dated May 27,1879; application filed October 22, 1878.

To all whom it may concern:

Be it known that I, GEO. H. GoRLIss, of the city and county ofProvidence, in the State of Rhode Island, have invented certain new anduseful Improvements relating to Steam-Engines and I do hereby declarethat the following is a full and exact description thereof.

My invention applies to the construction and arrangement ofexhaust-valves adapted to operate by being partially turned incylindrical cavities which are portions of the interior space in orconnected with the main cylinder.

I have discovered that by giving a peculiar form to the valve I can havethe valve-cavity partly intersect the main cavity of the main cylinder,and yet can turn the valve while the piston is at the extreme end of thestroke.

The following is a description of what I consider the best means ofcarrying out the invention.

The accompanying drawings form a part of this specification. Figure 1 isa central longitudinal section through an entire cylinder, with myvalves in operation near the termination of the stroke of the piston tothe left 5 Fig. 2, a corresponding section of a portion of the lowerpart alone, with the exhaust-valve shifted, showing how there is roomfor the required motion without striking the piston; Fig. 3, a view ofone of the exhaust-valves detached; and Fig. 4, a cross-section,showinga modification.

' Similar letters of reference indicate likeparts in all the figures.

A is the body of the main or steam cylinder, and B the cylinder-head.The cavity in the steam-cylinder is marked a. The exhaust-port leadingto the condenser is marked a. D is the piston, and D' the piston-rod.

The cavity for the exhaust-valve is marked e, and it partly intersectsthe steam-cavity a, as shown.

E is the exhaust-valve, semi-cylindrical in mid-length at E', andcylindrical at each end.

The cavity c', occupying half of the entire cross-section ofthe valve atits mid-length, allows the exhaust-steam to iiow past the valve whenopen, and allows the presence of the piston D without contact in all therequired working positions of the valve. This form, it will, beobserved, allows the valve to be turned to the fullest extent everrequired while the piston is in any part, or even at the extreme end, ofthe stroke.

The semi-cylindrical form E' is continued to near each end, where itchanges to a complete cylinder and completely lls the valve-cavity c.

In my improvement, as shown on the lefthand side in Fig. l, thevalve-cavity e is formed partly in the material ofthe cylinder andpartly in the material of the cylinder-head. It willbe understood thatwith this construction the cylinder is prolonged considerably beyond thetraverse of the pist-on, and that the head is correspondingly formed toapply within it.

ln a patent issued to me dated January 2, 1877, No. 185,855, I haveshown a mode ofcounecting the stem of a circular sliding valve so as toallow the valve to freely adjust itself upon its seat. I prefer to usesuch connection with this valve, but it is not'absolutely essential.

I have not deemed it necessary to show the mode of working the valve. Itwill be understood that I give the valve the proper vibrating or turningmotion by means of suitable connections to a stem or axis extending outthrough a stufng-box. (Not represented.)

It is not necessary that the exhaust-valve should lit steam-tight to theinterior of the valve-cavity c, except along the surfaces adjacent tothe exhaust-port a. The other portions oi the cavity need not fitclosely.' Itis only essential that it be large enough to allow the valveto turn, and not so much too large as to needlessly increase thecapacity of the valve-cavity.

My invention has nothing to do with steaminduction valves. I prefer tomount said steaminduction valves in very close proximity to thecylinder, and can attain this end in a very desirable manner by makingthe cavity for the steam-valves-entirely in the cylinder-heads B, asshown in Fig. 1.

The partial intersection of the main cylinder by the valve-cavities cfor the exhaustvalves by reducing the capacity of the space to be filledwith steam at each end of the cylinder, makes a material addition to thecconomic et't'ect of the steam over that which would be attained by theordinary arrangement, and the form of the valves, having the valve onlyindependent of the piston, so that it may be turned at any time with thepiston in any position.

I claim as my invention- The exhaust-valve E, semi-cylindrical in itsmid-length at E', and cylindrical at each end, as shown, arranged tooperate in the valvecavity e, which cavity partly intersects theinterior et of the steam-cylinder A, as and for the purposesherein setforth. f

In testi monywhereof I have hereunto set my hand this 16th day ofOctober, 1878, in the presence of two subscribing witnesses.

GEO. H. GORLISS.

Witnesses J EREMIAH MILLER, ED. W. RAYNSFORD.

